Thanks, Steve. That sounds like a straightforward modification to turn it into a headphone amp and I'm keen on trying it. I want to hear the magic in headphones that you mentioned in your CSP2 design notes, but I'm on a tight budget Portability is not an issue. Which do you think would sound better, a Zenhead or a ZSP1 configured as you described above?

Since the ZSP1 was not designed to be a headphone amp, I have no idea what the end result is going to be with this mod. My guess is the Zen Head would actually sound better. If the Zen Head was one of the typical portable headphone amps out there, I'd probably put my money on the tube unit sounding better, but right now the Zen Head is giving the CSP2 a serious run for it's money on headphones... it's just unusually good.